The invention relates to a window, facade and wall system which includes at least three panes of light-permeable and heat-permeable material such as glass or the like. The panes are separated from each other to delimit a number, n, of intermediary spaces therebetween. Lines or conduits conduct a heat-transfer medium, which optionally, could be colored and/or pigmented with colored or reflecting pigments through at least one of the intermediary spaces. A heat pump is provided in the circuit of the heat-transfer medium together with a switching means to regulate flow of the heat-transfer medium through no more than n-1 of the intermediary spaces.
One known system of utilizing environmental energy utilizes absorber elements arranged on the outer wall of a building. Heat is removed from the environment by these elements, which are usually large in area, and highly transformed by at least one heat pump so that it can be utilized for example for the preparation of warm water or for heating purposes. The use of heat pumps, which for example are electrically operated, as devices for the utilization of energy present in the environment is known.
Approximately three times the energy consumed can be obtained with the described system for heating purposes in average outdoor temperatures of just above 0.degree. C., which prevail in temperate zones in winter.
It is also known that the ratio of useful energy to energy consumed for the operation of a heat pump becomes increasingly disadvantageous with lowering outdoor temperatures and higher required temperature.
In the case of known outer-wall absorbers which can be attached to roofs or facades, energy is removed primarily from ambient air since the thermal insulation properties of the outer walls of the building located between the absorber surfaces and the inner area of the building can be correspondingly high.
A known weakness in the thermal insulation of any building is at the window areas because heat transition coefficients of below approximately 1.5 W/m.sup.2 K (heat transition coefficient for a finished window with frame) can not be obtained even if insulating glass is used. This heat transition coefficient is approximately 5 to 10 times greater than that of a good outer wall construction. It has been shown that in an average building having good outer insulation, approximately 50% of the heat transmission losses occur at the windows, with double glazing.
However, window areas present a problem not only in winter but also in summer. They are the critical area of a house facade with regard to protection from elevated outdoor temperatures. The summer heat load consists largely of heat radiation, which presently only can be prevented by shading or by reflection during its passage through window areas, or this passage at least can be reduced.
Windows, in contrast to good outer wall constructions having large masses, have no capacity to store heat. Therefore windows can not compensate for short-term temperature variations.
DE-OS 2 815 056 teaches a window which consists of four panes and in which a liquid heat-transfer medium is pumped through the middle intermediary space. Absorbed energy is removed from the medium by a heat-pump system.
DE-OS 2 736 137 describes a window consisting of more than five panes in which a heat-transfer medium does not flow through all the intermediary spaces. The heat-transfer medium, which can be colored, is conducted through the intermediary space adjacent a lower ambient temperature area. Stored energy also is removed by a heat pump from the heat-transfer medium according to DE-OS 2 736 137.